Drug companies are eager to produce a male birth control pill, which would allow men to take a daily medication that would prevent unwanted pregnancies in their partners. At this point, such a drug is still a pipe dream. However, a group of researchers has performed an experiment that may eventually lead to its development. By injecting a particular peptide into the testes of rats, the scientists discovered they could disrupt the blood-testes barrier, which results in sperm leaving the testes before they are developed enough to fertilize an egg. Though the experiments did not directly measure the fertility of the treated rats, previous work suggests that the level should be somewhere between low and non-existent. Additionally, unlike other potential roads to the male pill, this method appears to be reversible and, since the injected peptide is already produced by the body in limited amounts, safe — which are two major requirements the eventual pill will need to meet in order to make it to the market.

The human brain is likely the most complex subject studied and a recent experiment looked at how the brain organizes itself during development. The study examined mice with and without the gene Arl13b, which, when functioning correctly, allows neurons to read signals from the primary cilia, which guide the neurons to the right place. When the gene is knocked out or not functioning correctly, however, it’s like taking away the neurons’ road map and they get lost on their way to their intended destination. This results in a condition known as Joubert syndrome, which is linked with autism spectrum disorders as well as problems with brain structure. The study is among the first to see how the mutations of the gene actually affect brain development and will hopefully lead to more research that will help provide potential treatments for Joubert syndrome and similar diseases.

In our macroscopic world, if we watch a movie, we can generally tell if it’s moving forward or backward in time: People get older rather than younger and shards of a broken plate never fuse back together. In the subatomic world, however, things don’t work the same way, for the most part. Most processes that occur could just as easily have occurred in reverse. Researchers involved in the BaBar project at Stanford, however, have broken this time symmetry by demonstrating that a certain particle transformation is six times more likely to occur in one direction than the other when moving forward in time. What’s more, the certainty of this being a genuine result is impressive even by physical science’s standards: There is a greater chance of winning the lottery five times in a row than these results being the product of chance. This discovery is the result of 10 years of research with the BaBar project, which continues to investigate the subatomic world in the hopes of generating insights into the nature of time and matter.

A new study published in the journal PLOS One shows that fetuses yawn in the womb, even without having to sit through 8 a.m. lectures. The researchers used advanced 4-D ultrasound videos to differentiate between yawns and simple mouth movements of 15 healthy fetuses — eight girls and seven boys — measured over the second and third trimesters of a pregnancy. Based on the results, yawning appears to be an important part of development, though just like in post-birth humans, it’s unclear what its purpose is. Yawning is not, as commonly thought, a result of “forgetting to breathe,” though the phenomenon of a contagious yawn is very real and other research suggests that reading about yawning — for instance, this article — is also likely to induce yawns. The data collected here doesn’t make things much clearer in the big picture, though it does provide a more specific definition of in-utero yawns as well as support earlier findings that, over the course of a pregnancy, yawning is most frequent during the earlier stages and decreases to virtually nothing by the 36th week. As the reasons behind this phenomenon continue to remain unknown, it’s likely researchers will experience many more sympathetic yawns from studying the subject before they unravel this mystery.

Printed on Thursday, November 29, 2012 as: Birth control may use baby sperm